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1 | /* | |
2 | * Copyright © 2008 Keith Packard <keithp@keithp.com> | |
3 | * | |
4 | * This file is free software; you can redistribute it and/or modify | |
5 | * it under the terms of version 2 of the GNU General Public License | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program; if not, write to the Free Software Foundation, | |
15 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. | |
16 | */ | |
17 | ||
18 | #ifndef _LINUX_IO_MAPPING_H | |
19 | #define _LINUX_IO_MAPPING_H | |
20 | ||
21 | #include <linux/types.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/bug.h> | |
24 | #include <linux/io.h> | |
25 | #include <asm/page.h> | |
26 | ||
27 | /* | |
28 | * The io_mapping mechanism provides an abstraction for mapping | |
29 | * individual pages from an io device to the CPU in an efficient fashion. | |
30 | * | |
31 | * See Documentation/io-mapping.txt | |
32 | */ | |
33 | ||
34 | struct io_mapping { | |
35 | resource_size_t base; | |
36 | unsigned long size; | |
37 | pgprot_t prot; | |
38 | void __iomem *iomem; | |
39 | }; | |
40 | ||
41 | #ifdef CONFIG_HAVE_ATOMIC_IOMAP | |
42 | ||
43 | #include <asm/iomap.h> | |
44 | /* | |
45 | * For small address space machines, mapping large objects | |
46 | * into the kernel virtual space isn't practical. Where | |
47 | * available, use fixmap support to dynamically map pages | |
48 | * of the object at run time. | |
49 | */ | |
50 | ||
51 | static inline struct io_mapping * | |
52 | io_mapping_init_wc(struct io_mapping *iomap, | |
53 | resource_size_t base, | |
54 | unsigned long size) | |
55 | { | |
56 | pgprot_t prot; | |
57 | ||
58 | if (iomap_create_wc(base, size, &prot)) | |
59 | return NULL; | |
60 | ||
61 | iomap->base = base; | |
62 | iomap->size = size; | |
63 | iomap->prot = prot; | |
64 | return iomap; | |
65 | } | |
66 | ||
67 | static inline void | |
68 | io_mapping_fini(struct io_mapping *mapping) | |
69 | { | |
70 | iomap_free(mapping->base, mapping->size); | |
71 | } | |
72 | ||
73 | /* Atomic map/unmap */ | |
74 | static inline void __iomem * | |
75 | io_mapping_map_atomic_wc(struct io_mapping *mapping, | |
76 | unsigned long offset) | |
77 | { | |
78 | resource_size_t phys_addr; | |
79 | unsigned long pfn; | |
80 | ||
81 | BUG_ON(offset >= mapping->size); | |
82 | phys_addr = mapping->base + offset; | |
83 | pfn = (unsigned long) (phys_addr >> PAGE_SHIFT); | |
84 | return iomap_atomic_prot_pfn(pfn, mapping->prot); | |
85 | } | |
86 | ||
87 | static inline void | |
88 | io_mapping_unmap_atomic(void __iomem *vaddr) | |
89 | { | |
90 | iounmap_atomic(vaddr); | |
91 | } | |
92 | ||
93 | static inline void __iomem * | |
94 | io_mapping_map_wc(struct io_mapping *mapping, | |
95 | unsigned long offset, | |
96 | unsigned long size) | |
97 | { | |
98 | resource_size_t phys_addr; | |
99 | ||
100 | BUG_ON(offset >= mapping->size); | |
101 | phys_addr = mapping->base + offset; | |
102 | ||
103 | return ioremap_wc(phys_addr, size); | |
104 | } | |
105 | ||
106 | static inline void | |
107 | io_mapping_unmap(void __iomem *vaddr) | |
108 | { | |
109 | iounmap(vaddr); | |
110 | } | |
111 | ||
112 | #else | |
113 | ||
114 | #include <linux/uaccess.h> | |
115 | #include <asm/pgtable.h> | |
116 | ||
117 | /* Create the io_mapping object*/ | |
118 | static inline struct io_mapping * | |
119 | io_mapping_init_wc(struct io_mapping *iomap, | |
120 | resource_size_t base, | |
121 | unsigned long size) | |
122 | { | |
123 | iomap->base = base; | |
124 | iomap->size = size; | |
125 | iomap->iomem = ioremap_wc(base, size); | |
126 | #if defined(pgprot_noncached_wc) /* archs can't agree on a name ... */ | |
127 | iomap->prot = pgprot_noncached_wc(PAGE_KERNEL); | |
128 | #elif defined(pgprot_writecombine) | |
129 | iomap->prot = pgprot_writecombine(PAGE_KERNEL); | |
130 | #else | |
131 | iomap->prot = pgprot_noncached(PAGE_KERNEL); | |
132 | #endif | |
133 | ||
134 | return iomap; | |
135 | } | |
136 | ||
137 | static inline void | |
138 | io_mapping_fini(struct io_mapping *mapping) | |
139 | { | |
140 | iounmap(mapping->iomem); | |
141 | } | |
142 | ||
143 | /* Non-atomic map/unmap */ | |
144 | static inline void __iomem * | |
145 | io_mapping_map_wc(struct io_mapping *mapping, | |
146 | unsigned long offset, | |
147 | unsigned long size) | |
148 | { | |
149 | return mapping->iomem + offset; | |
150 | } | |
151 | ||
152 | static inline void | |
153 | io_mapping_unmap(void __iomem *vaddr) | |
154 | { | |
155 | } | |
156 | ||
157 | /* Atomic map/unmap */ | |
158 | static inline void __iomem * | |
159 | io_mapping_map_atomic_wc(struct io_mapping *mapping, | |
160 | unsigned long offset) | |
161 | { | |
162 | preempt_disable(); | |
163 | pagefault_disable(); | |
164 | return io_mapping_map_wc(mapping, offset, PAGE_SIZE); | |
165 | } | |
166 | ||
167 | static inline void | |
168 | io_mapping_unmap_atomic(void __iomem *vaddr) | |
169 | { | |
170 | io_mapping_unmap(vaddr); | |
171 | pagefault_enable(); | |
172 | preempt_enable(); | |
173 | } | |
174 | ||
175 | #endif /* HAVE_ATOMIC_IOMAP */ | |
176 | ||
177 | static inline struct io_mapping * | |
178 | io_mapping_create_wc(resource_size_t base, | |
179 | unsigned long size) | |
180 | { | |
181 | struct io_mapping *iomap; | |
182 | ||
183 | iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); | |
184 | if (!iomap) | |
185 | return NULL; | |
186 | ||
187 | if (!io_mapping_init_wc(iomap, base, size)) { | |
188 | kfree(iomap); | |
189 | return NULL; | |
190 | } | |
191 | ||
192 | return iomap; | |
193 | } | |
194 | ||
195 | static inline void | |
196 | io_mapping_free(struct io_mapping *iomap) | |
197 | { | |
198 | io_mapping_fini(iomap); | |
199 | kfree(iomap); | |
200 | } | |
201 | ||
202 | #endif /* _LINUX_IO_MAPPING_H */ |